| Perovskite solar cells（PSCs）have developed rapidly with the power conversion efficiency increased from 3.80%in 2009 to 25.73%at present.At the same time,PSCs have the advantages of simple preparation process and low cost.Therefore,PSCs have become a research hotspot in the energy industry.With the development of preparation technology and the progress of perovskite material system,the structure of PSCs has gradually developed from the original dye-sensitized structure to the current planar heterojunction structure,achieving high open-circuit voltage and strong photon absorption.However,the PSCs with planar structure are still facing following shortcomings:（1）When the voltage-ampere characteristic of perovskite solar cells is tested,the measured voltage-ampere characteristic curve will change due to the change of scanning direction and speed,resulting in hysteresis effect,which is difficult to obtain the real efficiency of perovskite solar cells;（2）The lack of mesoporous layer increased the roughness of the morphology of perovskite film,resulting in the decline of the performance and stability of perovskite solar cells with the increasement of active area.These shortcomings limit the development of PSCs.For the hysteresis effect,although the current research shows that the hysteresis effect may originate from the ion migration in the perovskite material,the traditional detection methods are basically aimed at the perovskite film and cannot carry out nondestructive characterization of the ion migration in the PSC.At the same time,the detection methods for defects in PSC,such as photoluminescence（PL）and electroluminescence（EL）,can only characterize the defect distribution,and cannot obtain the defect type and dynamic properties.Therefore,it is necessary to develop a new detection technology that can accurately characterize and analyze the hysteresis effect,defect types and dynamic characteristics of PSCs.The relevant research work in this thesis is based on the transient photoelectric detection technology,research and develop new non-destructive and quantitative characterization analysis technology,realize the detection of hysteresis effect,defect types and dynamic characteristics in perovskite solar cells,and provide theoretical and technical support for breaking through the bottleneck of large efficiency test error and complex defects in large area preparation of perovskite solar cells.The main research contents and results are as follows:1.For the damaging intensity of laser output,the photoresponse of perovskite materials was carefully investigated,then I have introduced a combined solution with LED and semiconductor laser which tuned bias and pulse light for the photon excitation.To match the drop time of the semiconductor laser and the sampling frequency of the signal corresponding to the detection technology,the characteristics of the carrier movement of perovskite solar cells was carefully investigated.In order to obtain the output power of semiconductor lasers in detection technology,the perturbation principle of light semiconductor interaction was studied.Finally,I completed the establishment of transient photoelectric perturbation detection,and realized the technology of detecting the carrier motion characteristics in perovskite solar cells by low energy transient perturbation.2.For the difficulty in characterizing ion migration of perovskite solar cells,the process of ion migration in planar heterojunction perovskite solar cells and the influence of ion migration on carrier motion was investigated,then I have introduced a method for quantitatively extracting differential capacitance to detect ion migration by using transient perturbation detection technology.In order to obtain the charge amount of the ion migration in the hysteresis effect,the established transient photoelectric perturbation detection platform was used,the carrier lifetime and concentration in the perovskite solar cell are modulated by controlling the output optical power of bias light,and the differential capacitance directly related to the ion migration in the perovskite solar cell is detected.The test results show that the degree of ion migration increases with the increase of irradiance.When the light intensity reaches 700 W/m2,the concentration of ion migration in MAPb I3-based perovskite solar cells reaches 5.65×10-12 mol/cm2,the quantitative characterization of the amount of ionic migration charge of hysteresis effect in perovskite solar cells has been realizing.3.For the identification of high-density defect types and dynamic characteristics in perovskite solar cells,the effect of different defects on carrier motion in perovskite solar cells was investigated,then I have developed the transient disturbance detection technology for carrier space-time processes based on the transient photoelectric disturbance detection technology.To obtain the high-density intrinsic point defects,surface defects,and grain boundary distribution of the perovskite solar cells,the carrier concentration and lifetime of different regions of perovskite solar cells was characterized and contrasted by controlling spatial position of transient photoelectric perturbation.Using this detection technology to test relevant devices,it was found that:（1）there was a transverse electric field caused by defects in perovskite solar cells,which is the reason for the decrease of short-circuit current in large area perovskite solar cells;（2）The concentration difference of ion migration in perovskite solar cells is related to the defect type;（3）The high-density intrinsic point defects of perovskite solar cells will affect the short-circuit current density and reduce the total current output of the solar cells. |
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